/**
 * Copyright (C) 2007 The AsyncMail Group <asyncmail@googlegroups.com>
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *         http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.googlecode.asyncmail.smtpserver.handler;

import com.googlecode.asyncmail.common.DSNStatus;
import com.googlecode.asyncmail.smtp.SMTPResponse;
import com.googlecode.asyncmail.smtp.SMTPResponseImpl;
import com.googlecode.asyncmail.smtp.SMTPRetCode;
import com.googlecode.asyncmail.smtpserver.SMTPSession;
import com.googlecode.asyncmail.smtpserver.hook.HookResult;
import com.googlecode.asyncmail.smtpserver.hook.QuitHook;

import java.util.ArrayList;
import java.util.Collection;

/**
 * Handles QUIT command
 */
public class QuitCmdHandler extends AbstractHookableCmdHandler {

    /**
     * The name of the command handled by the command handler
     */
    private final static String COMMAND_NAME = "QUIT";

    /**
     * Handler method called upon receipt of a QUIT command. This method informs
     * the client that the connection is closing.
     * 
     * @param session
     *                SMTP session object
     * @param argument
     *                the argument passed in with the command by the SMTP client
     */
    private SMTPResponse doQUIT(SMTPSession session, String argument) {
        SMTPResponseImpl ret;
        if ((argument == null) || (argument.length() == 0)) {
            StringBuffer response = new StringBuffer();
            response.append(
                    DSNStatus.getStatus(DSNStatus.SUCCESS,
                            DSNStatus.UNDEFINED_STATUS)).append(" ").append(
                    session.getConfigurationData().getHelloName()).append(
                    " Service closing transmission channel");
            ret = new SMTPResponseImpl(SMTPRetCode.SYSTEM_QUIT, response);
        } else {
            ret = new SMTPResponseImpl(
                    SMTPRetCode.SYNTAX_ERROR_COMMAND_UNRECOGNIZED, DSNStatus
                            .getStatus(DSNStatus.PERMANENT,
                                    DSNStatus.DELIVERY_INVALID_ARG)
                            + " Unexpected argument provided with QUIT command");
        }
        ret.setEndSession(true);
        return ret;
    }

    /**
     * @see com.googlecode.asyncmail.smtpserver.core.CommandHandler#getImplCommands()
     */
    public Collection<String> getImplCommands() {
        Collection<String> implCommands = new ArrayList<String>();
        implCommands.add(COMMAND_NAME);

        return implCommands;
    }

    /**
     * @see com.googlecode.asyncmail.smtpserver.handler.AbstractHookableCmdHandler#doCoreCmd(com.googlecode.asyncmail.smtpserver.SMTPSession,
     *      java.lang.String, java.lang.String)
     */
    protected SMTPResponse doCoreCmd(SMTPSession session, String command,
            String parameters) {
        return doQUIT(session, parameters);
    }

    /**
     * @see com.googlecode.asyncmail.smtpserver.handler.AbstractHookableCmdHandler#doFilterChecks(com.googlecode.asyncmail.smtpserver.SMTPSession,
     *      java.lang.String, java.lang.String)
     */
    protected SMTPResponse doFilterChecks(SMTPSession session, String command,
            String parameters) {
        return null;
    }

    /**
     * @see com.googlecode.asyncmail.smtpserver.handler.AbstractHookableCmdHandler#getHookInterface()
     */
    protected Class<?> getHookInterface() {
        return QuitHook.class;
    }

    /**
     * @see com.googlecode.asyncmail.smtpserver.handler.AbstractHookableCmdHandler#callHook(java.lang.Object,
     *      com.googlecode.asyncmail.smtpserver.SMTPSession, java.lang.String)
     */
    protected HookResult callHook(Object rawHook, SMTPSession session,
            String parameters) {
        return ((QuitHook) rawHook).doQuit(session);
    }

}
